I am not convinced. Yes, the regulations are a factor, but ego is also a factor. See also Giraffe Necks.
Yes, Europe and Asia have different cultures from North America. The impulse for ego may be biological, but the expression is cultural.
Also, trucks have some of the highest inventory levels of any new vehicle type right now. If ego is the only way to explain this, why did folks buy so many more trucks last year? Did the American ego Change more than gas prices?
If you re-read my comment, you may note that I did NOT say this.